Hot top



June 13, 1933. s. DUMAS ,9

HOT TOP Filed July 8, 1951 m I I Y I lNVEb {TOR Patenied .June 13, 1933 PATIENT OFFICE MAXWELL G. DUMAS, ZPITTSIBURGH, PENNSYLVANIA Application filed July 8, 1931. Serial No. 5491534.

This invention relates to hot tops or feeders for ingot molds, and it is among the objects of this invention to provide a hot top structure whichshall be adapted to facilitate the pouring of the metal in the mold in that the pouring may be done without interruption. 1

Another object of the invention is to provide a hot top structure which shall be of 0 simple construction and economical to manufacture. r I

Hot tops as heretofore constructed, are of various forms,some of which are adapted to be supp'ortedonthe top of an ingot mold by meansof a flange support and others are adapted to be suspended within the mold and adjusted to various heights dependent upon thesize of the ingot to be cast. In the latter type, a suflicient clearance must be provided between the hot top and the interior of the ingot mold to prevent binding of the members, on account of the slight distortions and inaccuracies resulting from the manufacture of the hottop. This clearance has heretofore been so great that when the metal is poured in the mold and reaches the level of the lower portion of the hot top, the pouring operation is suspended for sufficient length of time to' permit the molten metal rising in the clearance between the hot top and mold to freeze, after which the pouring is completed by filling the hot top for feeding metal to the ingotin a manner characteristic of all hot tops.

In accordance withthe present invention, I design the hot top to provide sufficient clearance to allow for manufacturing discrepancies, allowing a minimum clearance at a restricted portion preferably at the lowermost portion of the hot top. Such construction permits pouring=the ingot without interruption since the metal rising in the mold will envelop the lower region of the hot top filling in the slight clearance,-and due to the relatively small section of molten metal in' the restricted clearance portion, it will freeze almost instantly, thus sealing off the metal in the ingot mold against escape past the sides of the hot top.

In the accompanying drawing constituting "pended in an ingot mold 2 in any suitable manner and for any distance from the top of the mold, the means shown for supporting 9 the hot top being for'the purpose of illustration only and consists of lateral supports 3 which are fitted in holes provided in the side walls of the hot top to support it on top of the mold 2. A plurality of such holes may be vertically spaced on the sides of the hot top, so that the latter may be placed in a different positions in accordance with the size of the ingot it is desired to produce by inserting the lateral supports in the holes corresponding to the desired distance. This however is not a feature of my invention.

The top 1 is formed with side walls 4 which are straight in the vertical plane, but otherwise of the form of the interior of the mold 2, this form being illustrated at 9 in Figure 2 as being in the shape of a square, although it may be fluted or of other polygonal shapes.-

The other dimensions of the main body portion of the hot top are considerably less 9 than the inner dimensions of the mold 2, resulting in a large clearance space, shown at 5 in the drawing. Around the lower edge of the side wall of the hot top, I provide a peripheral flange or bead 6, the contour of I which iscomplementary to. theshape a: the interiorsurface of the mold. The outer dimension of, thebead 6 is greater than the dimensionof the side wall 4 but sufliciently less than the inner dimension of the mold 2 to permit free movement of the top for ver tical adjustment within the mold. The clearance between the head -6 and the interior I of the mold is so small that molten metal in the mold will freeze almost instantly in the clearance space when the ingot i being poured, thus sealing off the space 5in the upper region of the mold and causing the interior of, the hot top be filled with molten metal. I

By employing the bead 6, a substantial amount of material is saved in the construction of the hot'top since the thickness of the side walls will be reduced without sacrificing strength, and an additional advantage is obtained in that the head portion is so small in comparison with the vertical length of the hot top that even when the load is a close fit within the interior of the mold, no difiiculty will be experienced in placing the hot top in the proper position within the mold, whereas if the entire wall section were of the same dimension as the bead 6, any slight distortion in the surface would cause binding of the hot top in the ingot mold resulting in breakage if it were attempted to force the hot top into the mold.

The hot top 1 is otherwise constructed to possess an arched roof or top 7 and a restricted neck portion 8 which reduces croppage in the ingot and results in a more eiii cient feeding of the molten metal to the region where the pipe will form in the center of the ingot, the elimination of which is the object of employing hot tops in the casting of ingots.

i In the drawing, the ingot mold has been illustrated as a polygonal shape in the form of a. rectangle, the curve and corners of which are designed to cause the ingot to more readily free itself from the mold for reasons well known in the art. It will, however, be obvious that the improved form of hot top can be adapted to ingot molds of any geometrical form,"namely, round or of octagonal shape, since in any of these cases, a bond may be formed on the hot top which cooperates with the interior of the ingot mold.

Although one embodiment of the invention has been herein illustrated and described, it will be obvious to those skilled in the art that various modifications "may be made in the details of construction without depart-v ing from the principles herein set forth, as for example, in the location of the head 6 to portions other than the lower extremity of the hot top.

I claim herein as my invention:

1. A hot top for ingot molds comprising a hollow refractory body adapted to be partially suspended in the interior of a mold and having a peripheral flange of relatively small surface area and of the samecross sectional shape as the interior of the mold, said flange being integral with and extending outwardly from said hollow body and being of slightly less dimension than the interior of the mold whereby the molten metal rising in the mold freezes around the flange to form a seal without interrupting the pouring operation.

2. A hot top for ingot molds comprising a refractory body adapted to be suspended ina mold said refractory member having a heat deflecting top and a restricted neck portion 1,91 ease wall of the ingot mold to cause the metal to freeze around the flange when it rises to the level of the flange in the mold.

In testimony whereof I have hereunto set my hand.

MAXWELL G. DUMAS. 

